The military alliance is pushing members to increase their defence spending to five percent of GDP, under pressure from US President Donald Trump.

"We do not consider any rearmament by NATO to be a threat to the Russian Federation, because we are self-sufficient in terms of ensuring our own security," Putin told reporters, including AFP, at a televised press conference in Saint Petersburg.

He added that Russia was "constantly modernising our armed forces and defensive capabilities".

Though he conceded higher spending by NATO would create some "specific" challenges for Russia, the Kremlin leader said it makes "no sense" for NATO members themselves.

"We will counter all threats that arise. There is no doubt about that," he said.

Putin has cast his offensive in Ukraine as part of a wider conflict between Russia and NATO.

Kyiv is seeking security guarantees from NATO as part of any deal to end the fighting, more than three years after Russia ordered its full-scale military offensive.